Electron discharge device

ABSTRACT

An electron discharge device is provided having an anode comprising portions each having two or more inwardly extending fins to electrostatically extend the anode toward the interior electrodes. Each fin has a separate and independent direct heat path to an external heat radiator. Heat generated at the fins is thus conducted through angularly displaced thermal paths from the electrodes toward the envelope whereby the heat can be radiated evenly throughout the envelope.

United States Patent Ringeman 1 Feb. 8, 1972 [54] ELECTRON DISCHARGE DEVICE FOREIGN PATENTS OR APPLICATIONS [72] Inventor: Othmar E. Ringeman, St. Meinrad,1nd. 601,021 12/1959 ltaly ..L ..313/39 [7 3] Assignee: General Electric Company Primary Examiner koy Lake 22 i 24, 1970 Assistant Examiner-Darwin R. Hostetter Attorney-Nathan J Cornfeld, John P. Taylor, Frank L. Neu- PP 13,574 hauser, Oscar B. Waddell and Joseph B. Forman s21 U.S.Cl ..313/40,313/45, 313/46 [57] 7 ABSTRACT [51] lnt.Cl. .1101] 19/36 An electron discharge device is provided having an anode [58] Field of Search ..3l3/39,'40, 45,46 comprising portions each having two or more inwardly extending fins to electrostatically extend the anode toward the 56 mg Cited interior electrodes. Each fin has a separate and independent direct heat path to an external heat radiator. Heat generated UNITED STATES PATENTS at the fins is thus conducted through angularly displaced thermal paths from the electrodes toward the envelope whereby DlOUhy the heat can be radiated evenly throughout the envelope. 3,151,265 9/1964 Stephens...

Droppa ..313/39 3 Claims, 2 Drawing Figures PATENTEUFEB 8 I972 INVENTOR: OTHMAR E. RlNGEMAN M HIS ATTORNEY ELECTRON DISCHARGE DEVICE CROSS-REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION This invention relates to electron discharge devices and more particularly to such devices that are adapted for operation at relatively high power.

US. Pat. No. 3,151,265 issued Sept. 29, 1964 and assigned to the assignee of this invention describes and claims an anode structure for a beam power tube. The claimed anode structure inhibits emanation of spurious oscillations or snivets which are more fully described therein when such a tube is used, for example, in the horizontal deflection circuitry of television receivers. Briefly, the anode structure described therein extends the anode electrostatically toward the inner electrodes via an integral fin assembly.

While this construction successfully eliminated the electronic difficulties theretofore experienced, the construction resulted in a concentration of heat generated about the fin assembly, necessitating removal of the heat.

It has become the practice to construct such anode structures of laminated metals comprising a good heat conducting core such as copper and outer facing layers comprising aluminized or alitized iron which is a good heat radiator but a poor heat conductor. Thus, particularly when using such laminated anode material, heat removal in the structure of the above referenced patent is somewhat limited by the structural shape of the integral fin wherein the conducting heat path is via a single path.

In recent years this problem has been aggravated by higher plate power used to achieve greater deflection angles is television tubes due to the demand for flatter or narrower television sets.

It is therefore an object of the invention to provide an electron discharge device with an improved anode structure having means for more efficient removal of heat from the fin assemblies. Other objects of the invention will be apparent from the description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an isometric partially cutaway view of the invention.

FIG. 2 is a section view of FIG. 1 taken along lines II-II.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, an electron discharge device is generally indicated at 2 comprising an envelope 4, a cathode 6, a control grid 8, a screen grid 10, a beam plate 12, and an anode assembly 14.

As best seen in FIG. 2, anode 14 comprises two anode portions, 16 and 18. Each anode portion in turn comprises a pair of fin and radiator assemblies joined together by a channel member. Referring to anode portion 16, fin and radiator assembly 20 is shown joined to a second fin and radiator assembly 22 by a channel member 24. Anode portion 18 can be seen to be similarly formed.

Fin and radiator assembly 20 includes an inwardly extending fin 30 which serves to electrostatically extend the anode toward the inner electrodes of tube 2 for the electronic purposes previously noted. At the opposite end of assembly 20 is a radiator 40 positioned adjacent envelope 4 to radiate heat thereto. As can be seen in FIG. 2, each fin and radiator assembly comprises a unitary member providing an uninterrupted heat conduction path for the heat generated adjacent portion 30a of tin 30, which is closest to the internal electrodes, to flow to the radiator by conduction and to be radiated therefrom to the envelope. It should be noted that the heat is generated adjacent portion 30a of fin 30 by virtue of the concentration of electrons passing from the cathode to the anode in this area. The unitary member or sheet from which assembly 20 is formed is bent to form intermediate portions 32, 34, and 36 to lead the heat away from the adjacent electrodes to fin 40.

Channel member 24 is formed to provide an end wall 50, sidewalls 52 and 54, flanges 56 and 58, depending outwardly from the respective sidewalls. Fin and radiator assemblies 20 and 22 are joined together by suitably attaching portion 32 and assembly 20 to flange 56 of channel member 24 and portion 62 of assembly 22 to flange 58 of channel member 24. The attachment can be made by welding or by staking or riveting. When the attachment is made by means which will provide'openings in the joined pieces, a second portion 56a or 58a of the respective flange can be rolled back over the opening to provide a shield. This is necessary because one of the purposes of channel 24 is to shield glass envelope 4 from electrons emanating from the cathode. Any openings created by the joining of the channel to the adjacent fin and radiator assemblies must therefore be covered to prevent such deleterious emissions.

The second function of channel 24 is to provide a spacing between assembly 20 and assembly 22. This spacing allows the heat generated by fins 30 and 60 on the respective assemblies to flow independently to the respective heat radiators without providing a heat flow constriction and resulting hot spot such as might occur if channel 24 were omitted and fins 30 and 60 placed adjacent one another.

The joining together of assemblies 20 and 22 via channel 24 provides a relatively low heat conductivity path between the assemblies and thus the advantages just discussed are not mitigated by this joining. It should be noted in this regard that it has become the practice to construct anodes of laminated layers of metal comprising a heat conducting core such as copper faced on both sides with a layer of iron having an aluminized or alitized surface which is a good heat radiator but a poor heat conductor. Thus when the assemblies are made of such material, heat conduction through channel 24 will be small compared with the amount of heat conducted to the radiators.

The foregoing description, addressed to anode portion 16, applies equally to anode portion 18 which, as. can be seen in FIG. 2, is the mirror image .of anode portion 16. Thus four fins are provided, each having an independent, separate, and direct heat path to a heat radiator. The four heat radiators are angularly spaced apart to evenly radiate the generated heat to the envelope.

As seen in both FIGS. 1 and 2, anode portions 16 and I8 are not contiguous, but are spaced apart somewhat. This maintains the independence of eachheat path and further provides paths of escape for heat not carried away from the electrodes by the anode portions. The spacing apart of the anode portions as illustrated does not result in the bombardment of envelope 4 by electrons from cathode 6 as previously discussed with regard to channel member 24. Such bombardment is prevented by beam plate I2 and the geometric location of grid supports 70, 70a, 72, and 72a as well as the provision of inwardly extending tabs 80, 82, 84, and 86 respectively carried by heat radiators 40, 42, 44, and 46. Tabs and 82, for example, extend generally toward one another a sufficient distant relative to the spacing apart of anode portions 16 and 18 to shield envelope 4 from any electrons emitted by'the cathode which would pass to either side of grid supports 70a and 72a, and through the openings in beam plate 12 of the tabs. This extension, it should be noted, is dimensioned not only to shield against direct line of flight emission of electrons from the cathode, but also secondary electrons diffracted from, for example, inner surface 36a of portion 36 by cathode electrons striking this surface.

Thus, an electron discharge device is provided having a construction suitable for dissipation of large amounts of heat; generated under high power conditions. The invention provides an anode structure in a tube capable of operating under high power conditions with minimum RF radiations by providing separate anode portions each having a plurality of fin members to extend the anode electrostatically toward the other electrodes and to independently and separately conduct the generated heat to heat radiators angularly spaced adjacent the envelope. While the invention has been described with reference to a preferred embodiment minor modifications of the invention will be apparent to those skilled in the art and are deemed to be within the scope of the invention as defined in the following claims.

lclaim:

1. An anode for an electron discharge device comprising an evacuated glass envelope having a cathode and at least one grid element therein comprising two spaced-apart anode portions, each of said anode portions comprising two spaced apart and independent fin and radiator assemblies each comprising a unitary member having fin means projecting toward said cathode and grid electrodes to electrostatically extend said anode toward said cathode and grid electrodes and heat radiating means positioned adjacent said envelope comprising four heat radiators angularly spaced apart to evenly radiate the generated heat to said envelope, said unitary member providing an uninterrupted and independent heat conduction path for the heat generated adjacent said fin means by conduction and to be radiated therefrom to said envelope.

2. The device asin claim 1, wherein said spaced-aparted fin and radiator assemblies are interconnected by a channel member of generally U-shaped cross section, the connection of said assemblies and channel member being a relatively lowheat conductivity path to allow the heat generated at each of said fin means'to flow independently to its respective heat radiator.

3. The anode of claim 1 wherein said unitary members are constructed of laminated metal having a heat conducting core and heat radiating surfaces so that heat generated adjacent said fin means on each member will flow to said radiator by conduction through the unitary member and flow from said radiator to said envelope by radiation. 

1. An anode for an electron discharge device comprising an evacuated glass envelope having a cathode and at least one grid element therein comprising two spaced-apart anode portions, each of said anode portions comprising two spaced apart and independent fin and radiator assemblies each comprising a unitary member having fin means projecting toward said cathode and grid electrodes to electrostatically extend said anode toward said cathode and grid electrodes and heat radiating means positioned adjacent said envelope comprising four heat radiators angularly spaced apart to evenly radiate the generated heat to said envelope, said unitary member providing an uninterrupted and independent heat conduction path for the heat generated adjacent said fin means by conduction and to be radiated therefrom to said envelope.
 2. The device as in claim 1, wherein said spaced-aparted fin and radiator assemblies are interconnected by a channel member of generally U-shaped cross section, the connection of said assemblies and channel member being a relatively low-heat conductivity path to allow the heat generated at each of said fin means to flow independently to its respective heat radiator.
 3. The anode of claim 1 wherein said unitary members are constructed of laminated metal having a heat conducting core and heat radiating surfaces so that heat generated adjacent said fin means on each member will flow to said radiator by conduction through the unitary member and flow from said radiator to said envelope by radiation. 